'Little brain' plays a major role in schizophrenia

Although the cerebellum (latin for "little brain") occupies only about 20% of the human brain, it actually contains about 70% of all its neurons. This brain structure has traditionally been thought of as responsible for body movement and coordination, and has therefore often been ignored in research on the biological basis of psychological functions and mental disorders.

The current study included brain scans from 2300 participants from 14 international sites. The researchers used sophisticated tools that allowed them to analyze both the volume and shape of the brain.

Surprisingly, the results showed that the cerebellum is among the brain regions with the strongest and most consistent differences in schizophrenia. On a group level, patients had smaller cerebellar volumes compared with healthy individuals. "These findings clearly show that the cerebellum plays a major role in schizophrenia," says lead author Torgeir Moberget.

Most mental disorders emerge during childhood and adolescence, and a better understanding of the causes may give better patient care. "To develop treatments that could reverse or even prevent the disease we need to understand why some people are at risk of developing these serious illnesses in the first place," says senior author Lars T. Westlye.

The large sets of data allowed the researchers to identify very nuanced differences in brain volume in patients when compared with healthy controls. "It is important to emphasize that the brain differences we see in schizophrenia are generally very subtle. This is one reason why large collaborative studies are so important," Moberget says. "When we saw the same pattern repeated across many groups of patients and controls from different countries, the findings became much more convincing."